Freaking out. I just need answers!

I went for an ultrasound last week and measured way behind.  My doctor ordered blood work 72 hours apart.  My levels did not rise but stayed consistent around 57,400.  Per my LMP, I should be 8 weeks 6 days.  Per first ultrasound, I should be 7 weeks 1 day.  I have another ultrasound tomorrow to try to find a heartbeat (no heartbeat at first U/S).  Anyone ever had levels not rise but still have everything turn out okay?? I just am so anxious and want an answer so bad so that I can either start planning or start grieving...